{	Problem: http://codeforces.ru/problemset/problem/75/A
	Verdict: Accepted
}
uses SysUtils;
var s,t,b:string;
begin
readln(s);
readln(t);
b:=inttostr(strtoint(s)+strtoint(t));
while pos('0',s)<>0 do delete(s,pos('0',s),1);
while pos('0',t)<>0 do delete(t,pos('0',t),1);
while pos('0',b)<>0 do delete(b,pos('0',b),1);
if strtoint(s)+strtoint(t)=strtoint(b) then write('YES') else write('NO');
end.